In this study, combustion performances and emission characteristics of olive cake and olive cake+coal mixture are investigated in a bubbling fluidized bed of 102 mm inside diameter and 900 mm height. The average particle sizes of coal and olive cake used in the experiments were 1.57 mm and 1.52 mm, respectively. Flue gas concentrations of O2, CO, SO2, NOx, and total hydrocarbons (CmHn) were measured during combustion experiments. Operational parameters (excess air ratio, secondary air injection) were changed and variation of pollutant concentrations and combustion efficiency with these operational parameters were studied. The temperature profiles measured along the combustor column was found higher in the freeboard for olive cake than coal due to combustion of hydrocarbons mostly in the freeboard. The location of the maximum temperature in the freeboard shifted to the upper part of the column, as the volatile matter content in the fuel mixture increased. Combustion efficiencies in the range of 83.6-90.1% were obtained for olive cake with the excess air ratio of 1.12-2.30. The corresponding combustion efficiency for coal was 98.4-99.7% under the same conditions. As the CO and hydrocarbon concentration in the flue gas increased, the combustion efficiency decreased. Also co-combustion experiments of olive cake and coal for various mixing ratios were carried out. As the amount of olive cake in the fuel mixture increased, SO2 emissions decreased because of the very low sulfur content of olive cake. In order to increase the combustion efficiency, secondary air was injected into the freeboard which was a good solution to decrease the CO and hydrocarbon emissions, and to increase the combustion efficiency. For the setup used in this study, the optimum operating conditions with respect to NOx and SO2 emissions were found as 1.35 for excess air ratio, and 30 L/min for secondary air flowrate for the combustion of 75 wt% olive cake and 25 wt% coal mixture. Highest combustion efficiency of 99.8% was obtained with an excess air ratio of 1.7, secondary air flow rate of 40 L/min for the combustion of 25 wt% olive cake and 75 wt% coal mixture.

Made available in DSpace on 2014-12-17T14:08:49Z (GMT). No. of bitstreams: 1 EdsonAA_DISSERT.pdf: 3674397 bytes, checksum: 68989b5d2aabcb74990cc326c009fbc6 (MD5) Previous issue date: 2012-02-17 / The method "toe-to-heel air injection" (THAITM) is a process of enhanced oil recovery, which is the integration of in-situ combustion with technological advances in drilling horizontal wells. This method uses horizontal wells as producers of oil, keeping vertical injection wells to inject air. This process has not yet been applied in Brazil, making it necessary, evaluation of these new technologies applied to local realities, therefore, this study aimed to perform a parametric study of the combustion process with in-situ oil production in horizontal wells, using a semi synthetic reservoir, with characteristics of the Brazilian Northeast basin. The simulations were performed in a commercial software "STARS" (Steam, Thermal, and Advanced Processes Reservoir Simulator), from CMG (Computer Modelling Group). The following operating parameters were analyzed: air rate, configuration of producer wells and oxygen concentration. A sensitivity study on cumulative oil (Np) was performed with the technique of experimental design, with a mixed model of two and three levels (32x22), a total of 36 runs. Also, it was done a technical economic estimative for each model of fluid. The results showed that injection rate was the most influence parameter on oil recovery, for both studied models, well arrangement depends on fluid model, and oxygen concentration favors recovery oil. The process can be profitable depends on air rate / O m?todo toe-to-heel air injection (THAITM) ? um processo de recupera??o de petr?leo avan?ado, que consiste na integra??o da combust?o in-situ com os avan?os tecnol?gicos na perfura??o de po?os horizontais. Este m?todo utiliza po?os horizontais como produtores de ?leo, mantendo po?os injetores verticais para a inje??o de ar. Este processo ainda n?o foi aplicado no Brasil, tornando necess?rio, avalia??o destas novas tecnologias aplicadas ?s realidades locais, por isso, este trabalho teve como objetivo principal realizar um estudo param?trico do processo de combust?o in-situ com produ??o de ?leo em po?os horizontais, usando um reservat?rio semi sint?tico, com caracter?sticas das encontradas no Nordeste Brasileiro. As simula??es foram realizadas em um programa comercial de processos t?rmicos, denominado STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator), da empresa CMG (Computer Modelling Group). Foram realizadas an?lises dos par?metros operacionais: vaz?es de inje??o, configura??o dos po?os e concentra??o de oxig?nio. O estudo de sensibilidade dos fatores foi realizado com a t?cnica de an?lise de planejamento experimental, com uma combina??o de dois e tr?s n?veis (32x22), totalizando 36 simula??es, 18 para cada modelo, em fun??o da produ??o acumulada de ?leo (Np). Tamb?m foi realizada uma estimativa econ?mica de an?lise de custo para cada modelo de fluido. Os resultados mostraram que a configura??o de po?os e a vaz?o de inje??o foram o par?metro que apresentou maior influ?ncia no ?leo recuperado para os dois modelos de fluidos analisados, respectivamente, que a configura??o de po?os ? influenciada pelo modelo de fluido, e que um aumento da concentra??o de oxig?nio favorece a recupera??o de ?leo, no processo estudado. Tamb?m foi encontrado que o processo pode ser rent?vel dependendo da quantidade de ar injetado no processo

Made available in DSpace on 2014-12-17T14:08:54Z (GMT). No. of bitstreams: 1 HumbertoSC_DISSERT.pdf: 7792135 bytes, checksum: 5204c60825f60e9f74c5f24e46e8aa4e (MD5) Previous issue date: 2013-07-29 / Nearly 3 x 1011 m3 of medium and light oils will remain in reservoirs worldwide after conventional recovery methods have been exhausted and much of this volume would be recovered by Enhanced Oil Recovery (EOR) methods. The in-situ combustion (ISC) is an EOR method in which an oxygen-containing gas is injected into a reservoir where it reacts with the crude oil to create a high-temperature combustion front that is propagated through the reservoir. The High Pressure Air Injection (HPAI) method is a particular denomination of the air injection process applied in light oil reservoirs, for which the combustion reactions are dominant between 150 and 300?C and the generation of flue gas is the main factor to the oil displacement. A simulation model of a homogeneous reservoir was built to study, which was initially undergone to primary production, for 3 years, next by a waterflooding process for 21 more years. At this point, with the mature condition established into the reservoir, three variations of this model were selected, according to the recovery factors (RF) reached, for study the in-situ combustion (HPAI) technique. Next to this, a sensitivity analysis on the RF of characteristic operational parameters of the method was carried out: air injection rate per well, oxygen concentration into the injected gas, patterns of air injection and wells perforations configuration. This analysis, for 10 more years of production time, was performed with assistance of the central composite design. The reservoir behavior and the impacts of chemical reactions parameters and of reservoir particularities on the RF were also evaluated. An economic analysis and a study to maximize the RF of the process were also carried out. The simulation runs were performed in the simulator of thermal processes in reservoirs STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator) from CMG (Computer Modelling Group). The results showed the incremental RF were small and the net present value (NPV) is affected by high initial investments to compress the air. It was noticed that the adoption of high oxygen concentration into the injected gas and of the five spot pattern tends to improve the RF, and the wells perforations configuration has more influence with the increase of the oil thickness. Simulated cases relating to the reservoir particularities showed that smaller residual oil saturations to gas lead to greater RF and the presence of heterogeneities results in important variations on the RF and on the production curves / Aproximadamente 3 x 1011 m3 de ?leos m?dios e leves restar?o nos reservat?rios ao redor do mundo ap?s a aplica??o dos m?todos convencionais de recupera??o e grande parte desse volume seria recuper?vel com o uso de m?todos especiais. A combust?o in-situ (CIS) ? um m?todo de recupera??o avan?ada de petr?leo no qual um g?s que cont?m oxig?nio ? injetado no reservat?rio onde reage com o ?leo cru para criar uma frente de combust?o de alta temperatura que se propaga pelo reservat?rio. O m?todo HPAI (High Pressure Air Injection) ? uma denomina??o particular do processo de inje??o de ar aplicado em reservat?rios de ?leos leves, onde as rea??es de combust?o s?o dominantes entre 150 e 300?C e a gera??o de flue gas ? o principal fator de deslocamento do ?leo. Um modelo de simula??o de fluxo de um reservat?rio homog?neo foi constru?do para o estudo, o qual foi inicialmente submetido ? produ??o prim?ria, por 3 anos, e em seguida, ao processo de inje??o de ?gua por mais 21 anos. Nesse ponto, com a condi??o madura estabelecida no reservat?rio, foram selecionadas tr?s varia??es desse modelo, de acordo com o fator de recupera??o (FR) obtido, para o estudo da t?cnica de combust?o in-situ (HPAI). Em seguida realizou-se uma an?lise de sensibilidade sobre o FR de par?metros operacionais pr?prios do m?todo: vaz?o de inje??o de ar por po?o, concentra??o de oxig?nio no g?s injetado, esquema de inje??o de ar e configura??o dos canhoneados dos po?os. Essa an?lise, para um per?odo adicional de at? 10 anos produ??o, foi efetuada com o aux?lio da t?cnica de planejamento composto central. O comportamento do reservat?rio e os impactos de par?metros envolvendo as rea??es qu?micas e de particularidades de reservat?rio sobre o FR tamb?m foram avaliados. Adicionalmente foram elaborados uma an?lise econ?mica e um estudo de maximiza??o do FR do processo. As simula??es foram realizadas com o simulador de processos t?rmicos em reservat?rios STARS (Steam, Thermal and Advanced Process Reservoir Simulation) da CMG (Computer Modelling Group). Os resultados mostraram que os FR incrementais foram baixos e que o valor presente l?quido (VPL) ? impactado negativamente pelos elevados investimentos iniciais para compress?o do ar. Observou-se que a ado??o de maiores concentra??es de oxig?nio no g?s injetado e do esquema de inje??o de ar tipo five spot tende a favorecer o FR, e que a configura??o dos canhoneados dos po?os apresenta influ?ncia crescente com o aumento da espessura porosa com ?leo do reservat?rio. Casos simulados referentes ?s particularidades de reservat?rio indicaram que menores satura??es residuais de ?leo ao g?s levam a FR maiores e que a exist?ncia de heterogeneidades resulta em varia??es consider?veis nos FR e nas curvas de produ??o